Find the sum of the arithmetic series -12-9-6-...39.
a = -12
d = 3
S = n/2 (-12 + 39)
Your mission, should you choose to accept it, is to figure out how many terms there are (n) from -12 to 39
d = 3
S = n/2 (-12 + 39)
Your mission, should you choose to accept it, is to figure out how many terms there are (n) from -12 to 39